Answer: $ 182.5
Explanation:
The expected value of occurring events
having probabilities
is given by :-

Given : On any given day, a salesman can earn $0 with a 45% probability, $250 with a 25% probability, or $400 with a 30% probability.
i.e. Probability of earning $0 = 0.45
Probability of earning $250=0.25
Probability of earning $400=0.30
Then , the expected earnings is given by :-

Hence, the his expected earnings is $182.5.